On Sat, Feb 9, 2013 at 8:38 PM, Dominique Michel <dominique.michel@vtxnet.ch> wrote:

In the past, I done such a rt conversion on a dsp. It was working very
well but need some parameters to be carefully chosen. The only way to
chose those parameters are with a visual signal analysis. The timbre of
an instrument is unique, vary with the time and with the play. I used a
memory oscilloscope to do this analysis.

To be fair, real-time pitch to midi is not a linux audio problem but a general DSP problem that so far as I know, is far from solved on any platform. If your solution works as well as you say then you need to put it in a product and market it asap! This is something that I know people have sought for a long time. Even purpose built high-end hardware units, like the Axon series coupled with something like a Godin Synth Access guitar, have limitations and require the player to adapt to those limitations.